Solve the following equations for the unknown variable:

Question

Solve the following equations for the unknown variable:

a). 4x²=1600

b). 1/2x=12

c). square root of x=7

d). 3^x=81

Answer 1

x²=1600/4 = 400

x = +/- squareroot(400) = +/- 20

b (1/2)x = 12

x = 12*2 = 24

c sqrt(x) = 7

x = 7² = 49

d 3^x=81

log(base 3) 81 = x

log 81 / log 3 = 4

or 3*3*3*3 = 81, so x = 4.